coherency.mtm: Calculates Frequency Domain Coherence
In driegert/transfer: Frequency Domain Transfer Function Estimation Tools

Estimates and returns the Loeve spectrum given series x and y.

coherency.mtm(x, y = NULL, xySectioned = FALSE, n = NULL,
  forwardCoh = TRUE, freqRange = NULL, freqOffset = NULL,
  slideFreq = NULL, slideIdx = 1, nw = NULL, k = NULL, deltat = 1,
  nFFT = NULL, nFFT.add = 3, blockSize = NULL, overlap = NULL,
  adaptive = TRUE, jackknife = FALSE, prewhiten = FALSE,
  removePeriodic = TRUE, sigCutoff = NULL, nodes = 1,
  clusterType = c("SOCK", "MPI"))

`x`	A `vector` of values for the first dataset.
`y`	A `vector` of values for the second dataset - if null, assumes ... I'm not sure actually.
`xySectioned`	A `logical` denoting whether the data has already been sectioned. `FLASE` implies that the code will be sectioned according to `blockSize` and `overlap`.
`n`	A `numeric` value giving the length of the `x` and `y` data sets. If `NULL`, will be determined in the function.
`forwardCoh`	A `logical` value indicating if the forward coherence (`TRUE`) or reverse coherence `FALSE` should be computed.
`freqRange`	A `vector` of two values containing the range of frequencies to use. This range should be contained within [0, 1/(2*`dt`)] (0 to Nyquist)